It has long been known that low temperatures adversely affect the efficiency of storage batteries as a consequence of which they can and often do become incapable of starting the engines of motor vehicles in cold weather.
Battery failures from this cause can be avoided by heating it when temperatures fall below a predetermined level. Various proposals have been made to provide thermostatically controlled heating means for heating batteries within an insulated chamber or compartment. One such proposal was to use the battery to energize the means by which it was to be heated. Another proposal was to employ catalytic heaters within the chamber with the heaters provided with their own fuel supply. Storage batteries have also been heated within an insulated chamber by means of thermostatically controlled heater circuits connectable to outside circuits. It was an earlier practise to place a household electric lamp, connected to the household circuit under the hood to facilitate engine starting.